Pallets made of sheet material, such as corrugated fiberboard or paperboard, are known in the art and have been commercially available previously. Such are disclosed, for example, in U.S. Pat. Nos. 4,185,565 to Nymoen; 4,563,377 to Melli; and 4,867,074 to Quasnick. Methods and equipment for manufacturing such pallets, or parts therefor, are disclosed, for example, in U.S. Pat. Nos. 5,083,996 to Smith; and 5,154,687 to Jeslis.
Such prior devices and methods of manufacturing the same have not been totally satisfactory since they often require the forming of a number of multiple fold beam elements which are disposed and secured substantially normal to each other to define an open gridwork for supporting a load. Such prior pallets which have normally disposed elongate beams extending transversely of each other, as in Quasnick, provide spaces between the gridwork of beams, which may not provide adequate support for a load, and also are expensive to produce.
Where a pallet has been disclosed with upper and lower sheet elements and support members defined therein, such as in Nymoen, there have been concerns for strength and stability of the elements under the effects of heavy loads and rough handling. For example, the Nymoen disclosure merely has upper and lower sheet members secured together spanning the space between channel members, which may be insufficient to support loads which do not fully span the distance between the channel members. For example, a load which rests only between the spaced channel members in Nymoen could produce substantial buckling, or cupping, of the platform.
Accordingly, it is an object of the present invention to provide a novel pallet, made of sheet material, such as corrugated fiberboard, paperboard, or other light material, which is economical to manufacture, yet which provides substantial load supporting strength and stability.
Another object of the present invention is to provide a novel pallet made of sheet material which has a platform sheet secured to and supported by two or more spaced support members, with an end margin portion of the platform sheet which substantially spans the space between the support members adapted to be folded into a position extending at a substantial angle relative to remainder portions of the platform sheet to provide added load carrying strength in the space between the support members.
A further object of the present invention is to provide a simple and economically constructed pallet of sheet material, which includes a base sheet having at least a pair of spaced elongate channel members extending longitudinally of the base, with a platform sheet overlying and secured to the base. A marginal edge portion of the base is wrapped over and secured to the upper surface of a side edge margin of the platform sheet. This wrap-over construction adds columnar strength to the channel members adjacent the outer edges of the pallet permitting them to sustain and resist forces imposed upon the pallet, such as sideways forces resulting from using a forklift to position the pallet. The wrap-over feature also serves to strengthen the securing of the platform sheet to the base sheet without requiring additional tooling or machining.
Yet another object of the present invention is to provide a novel pallet having a base sheet with elongate channel members formed therein extending longitudinally of the base, which channel members have reinforcing members therein extending from a bottom wall of the channel member to the platform sheet overlying the channel.
A still further object of the present invention is to provide such a novel pallet wherein the reinforcing members include substantially rigid tubes disposed in an upright position in the channel members. The tubes have good resistance to compression, and thus aid in supporting loads placed on the platform sheet.
Another object of the present invention is to provide a novel method for the manufacture of such a pallet which includes the steps of forming a base sheet having elongate channel sections, forming a platform sheet which is placed on the base sheet, and folding side edge margins of the base sheet over side edges of the platform sheet and securing them thereto.
Further, a method is provided for producing a pallet which includes the steps of forming a base from a sheet of material by producing multiple folds in the sheet to provide at least two spaced support members depending from remainder portions of the sheet, forming a platform sheet having a width sufficient to span the distance between the support members, folding an end edge margin portion of the platform sheet at a substantial angle relative to remainder portions of the platform sheet, and securing the platform sheet on the base with the end edge margin portion spanning the space between support members.
These and other objects and features of the invention will become more clearly apparent as the following description is read in conjunction with the drawings.